387
J. Chem. Eng. Data 1980, 25, 387-388
Viscosity of Ortho-Substituted Aromatic Amines Ervin VQrtesi Research Institute for Heavy Chemical Industries, Veszprgm, Hungary Table I. Purity and Density of Aromatic Amines Tested Vlscoslty measurements were carrled out on eight ortho-substituted aromatlc amlnes at 293, 298, 303, 308, 310, 313, 318, 323, and 372 K temperatures. The actlvatlon enthalpy of viscous flow was determlned. The vlscosity In the 293-373 K range can be calculated wlthln an error of 6 % from the average activatlon enthalpy of related compounds (alkylated derivatives).
purity wlw density X lom3,kg m-3
99 >98 >99 -91 -98 -98 >98 91-98
A OT OEA DMA MEA DEA KA DMA
No viscosity data can be found in the literature relating to orthesubstituted aromatic amines which are liquids at ambient temperature, expect for aniline and o-toluidine. The empirical or semiempirical correlations proposed for the calculation of viscosity proved useless for our purposes. This is so partly because there is no nitrogen increment published for Thomas' method ( I ) , and the effects of substituents are also unknown. The viscosity of aromatic amines which form associates via hydrogen bonds can be calculated only with large error with Souders' method (2). The ortho 2,6disubstituted aromatic amines are indispensable intermediates in the pesticide chemistry. Therefore, the knowledge of their viscosity and the temperature dependence of their viscosity is a must.
1.022 1.0053 0.988 0.98 0.968 0.958 1.22 1.526
'"1 I
t i f 3' A
i n X A 0
or
A OE4 b OM4 0 M A E A 0 KA KMA
*
Experimental Sectlon The purity and density data of the aromatic amines tested, aniline (A), o-toluidine (OT), 2-ethylaniline (OEA), 2,6dimethylaniline (DMA), 2-methyl-6-ethylaniline(MEA), 2,6diethylaniline (EA), 2-chloroaniline (KA), and 2chloro-6-methylaniline (KMA), are listed in Table I. The dynamical viscosity of the above aromatic amines was determined by a Type BH Hoeppler viscosimeter. The time of fall of the ball between the two extreme works was determined with a digital timer accurate to 0.1 s which gave an error in the measurement of viscosities of fO. 1% . Temperature control using ZI calibratedthermometer was better than fO.l K. Viscosities were determined in the 293-372 K range, at nine temperature settings. The densities of the aromatic amines were measured by pycnometry taking into account volume changes of the pycnometer at the higher temperatures. Thus the error is about f0.001 g/cm3.
d
i.1 0 ~ 2f7
F
2,B
2,9
3.0
Measured viscosity values are listed in Table 11. The activation enthalpy of viscous flow reads as
H* := -RT2(d In t / d T ) p
(1)
After integration and rearrangement
= A exp(AH/RT)
(2)
After linearization In 7 = h A
+ AH/RT
(3)
I t can be seen from eq 3 that a linear relationship exists between the logarithm of dynamical viscosity and the reciprocal absolute temperature. This notion is sustantiated by the mea0021-956818011725-0387$01.00/0
21
3,2
3,3
3,4
c
m 1. Temperatwedependence of the viscosity of aromatic amines.
sured data (cf. Figure 1). The measured values fit a straight line. The coefficients of this straight line can be obtained by regression analysis (cf. Table 111). Y = Bo
Results and Dlscusslon
T]
.
.
+ B,X
(4)
It can be seen in both Figure 1 and Table I11that the viscous of aromatic amines at constant temperature-except those of the chloro derivatives-are very similar. Therefore, the viscosities of the alkylated derivatives can be averaged. The coefficients of eq 4 can be also determined from the averaged data. Those values yield the Intercept and the activationenthalpy of viscous flow (cf. Figure 2). In A = -3.5796 AH* = 17.705 kJ m0l-l K-l Thus, the viscosity of OriWsubstituted alkylated aromatic amines can be calculated by the equation
9 = 2.789 X IO-' exp(17705/RT) 0 1980 American Chemical Society
(5)
388
J. Chem. Eng. Data 1980, 25,388-390
Table 11. Viscosity of Aromatic Amines dynamical viscosity, mPas A OT OEA DMA MEA DEA KA KMA
293 K
298 K
303 K
308 K
311 K
313 K
318 K
323K
372K
47.08 44.50 45.00 37.40 38.70 43.70 39.44 25.60
39.95 37.25 38.50 32.60 33.50 36.50 34.00 22.63
34.20 32.55 33.25 28.32 29.50 32.45 29.31 20.14
30.00 28.20 29.15 25.00 26.00 28.50 26.26 17.99
26.30 25.60 25.90
25.97 24.85 25.24 22.26 23.52 25.45 23.68 16.14
22.55 21.50 21.80 19.50 20.45 22.00 21.50 14.50
20.00 19.40 19.50 18.57 18.20 20.00 19.56 13.65
9.1 8.9 9.1
23.90 26.80
8.7 9.3
Table 111. Coefficients of the Linear Regression Model and the Activation Enthabv of Viscous Flow Calculated from Coefficients A OT OEA DMA MEA DEA KA DMA
-3.8974 - 3.775 1 -3.7683 -4.1801 -3.3969 -3.4827 -3.8292 -3.6954
2246.72 2194.39 2198.07 228 2.2 3 2051.69 2107.30 2192.42 2030.27
" H = enthalpy of viscous flow. number of experimental points.
18.685 18.250 18.281 18.981 17.063 17.526 18.225 16.885
0.994 0.944 0.993 0.997 0.997 0.996 0.997 0.998
R = regression factor.
N=
The average relative error of the viscosities of the aromatic amines tested, calculated by eq 5, is 5.96%. Literature Cited
f 10'
(1) Thomas, L. H. J . Chem. SOC.1948, 573. (2) Souders, M. J . Am. Chem. SOC. 1938, 60, 154.
c 2,7
2,8
2,9
30
3,)
32
13
314
Flgure 2. Average viscosity of alkylated aromatic amines.
Received for review November 8, 1979.
Accepted June 9, 1980.
Thermodynamic Properties of Solutions Containing an Aliphatic Amine. 1. Excess Volumes of Binary Systems of Triethylamine with Benzene, Toluene, Ethylbenzene, and Isomeric Xylenes at 313.15 K Yarramareddy Pitcha
Rao and
Sushi1 K. Suri"
Chemistry Department, Indian Institute of Technology, Hauz Khas, New Delhi- 1100 16, India Table I. Phvsical Promrties of Liquids Used
Excess volumes, VE, of binary mixtures of triethylamine with benzene, toluene, ethylbenzene, and three isomeric xylenes at 313.15 K have been computed from the experimental density data. decreases when an alkyl group is added to the benzene ring. For Isomeric xylenes, It follows the order m-xylene > o-xylene > p-xylene. Introduction As a part of our investigations on the thermodynamics of binary mixtures (7-3), we considered it worthwhile to study in detail the dependence of each thermodynamic property of the binary mixture of representative aliphatic amines on the nature 0021-956818011725-0388$01.00/0
density at 313.15 K solvent
our value
triethylamine benzene toluene ethylbenzene o-xylene rn-xylene p-xylene
0.709 59 0.857 63 0.847 25 0.84940 0.862 83 0.847 15 0.843 83
refractive index (298.15 K)
lit. value lit. value (6) ourvalue (6) 0.7092= 1.3980 1.398 Ob 1.4980 1.497 92 0.8576 1.4940 1.494 13 0.8482 1.4932 1.493 20 0.8494 0.8633 1.5028 1.502 95 0.8471 1.4946 1.494 64 1.4932 1.493 25 0.8436
Calculated from the modified Rackett equation (8) with ZRA = 0.26992 adjusted to the density value at 298.15 from ref 6. Reference 7.
0 1980 American Chemical Society
